| 摘要: |
| 本文针对高硅铝微波管壳激光封焊工艺进行优化与机理讨论，通过单因素试验和正交试验对各工艺
参数进行优化，并通过SEM、EDS、金相测试和氦质谱检漏仪进行性能表征。结果表明，硅铝激光焊接熔池深
度主要受峰值功率影响，而熔池宽度主要受脉冲宽度影响，得到最佳工艺参数为：峰值功率2.4 kW、脉冲宽度
5 ms、脉冲频率20 Hz、焊接速度100 mm/min；离焦方式为负离焦，离焦量4 mm；脉冲波形为“预热-保温-缓
冷”波形，封焊后管壳漏率为9.7×10-10 Pa·m3
/s，并对管壳进行温度循环、稳态湿热、稳态振动和温度冲击等环
境试验后，漏率仍小于1×10-9
Pa·m3
/s，满足国军标要求。实现高硅铝合金良好封焊的机理为：最佳封焊工艺控
制了熔池中脆性Si相晶粒的长大，分布细小均匀的Si颗粒使得焊缝具有良好的韧性与强度，从而避免焊接裂纹
的产生。 |
| 关键词: 高硅铝管壳 激光焊接 工艺优化 气密性 封焊机理 |
| 基金项目: |
|
| Optimization of Laser Welding Process for High Silicon Aluminum Shell in Aerospace Microwave Applications |
|
Wang Yi Liu Shuai Lei Jie Dang Zuohong Zhao Pengsen Gao Yangtao
|
|
Avic Forstar Science and Technology Co., Ltd, Xi’an, 710077
|
| Abstract: |
| This article focuses on the optimization and mechanism discussion of laser sealing and welding process
for high silicon aluminum microwave shells. The process parameters are optimized through single factor experiments
and orthogonal experiments, and the performance is characterized by SEM, EDS, metallographic testing, and helium
mass spectrometer leak detector. The results showed that the depth of the silicon aluminum laser welding melt pool was
mainly affected by the peak power, while the width of the melt pool was mainly affected by the pulse width. The optimal
process was obtained as follows: peak power of 2.4 kW, pulse width of 5 ms, pulse frequency of 20 Hz, welding speed
of 100 mm/min, negative defocusing method, defocusing amount of 4 mm, pulse waveform of preheating insulation
slow cooling waveform. After sealing, the leakage rate of the shell was 9.7×10-10 Pa·m3
/s. After temperature cycling,
steady-state wet heat, steady-state vibration, and temperature shock environmental tests on the shell, the leakage rate
was still less than 1×10-9
Pa·m3
/s, meeting the requirements of the national military standard. The mechanism for
achieving good sealing of high silicon aluminum alloys is that the optimal sealing process controls the growth of brittle
Si phase grains in the melt pool, and the evenly distributed Si particles make the weld have good toughness and strength,
thereby avoiding the occurrence of welding cracks. |
| Key words: high silicon aluminum shell laser welding process optimization air tightness sealing mechanism |
